Electrical condenser



Jan. 19, 1932. B. J. BUTLER 1,841,572

ELECTRICAL CONDENS ER Filedpril 20, 1926 3 Sheets-Sheet 1 ELECTRICALcoNDENsER v Suva to z @W www,

Jan. 19, 1932. B J; BUTLER 1,841,572

ELECTRICAL CONDENS ER Filed April 20. 1926 3 Sheets-Sheet C5 M 12g, do.

Patented Jan. 19, 1932 UNITED STATES- .PATENT OFFICE BENJAMIN J'.BUTLER, OF SOMERVILLE, MASSACHUSETTS, ASSIGNOR, BY MESNE AS,-

` BIGNMENTS, TO. GENERAL ELECTRIC COMPANY, A CORPORATION' 0F NEW YORKELECTRICAL Application lcd April 20,

This invention relates to electrical condensers, more particularly tothose adapted l connections;

for high duty, as to potential, amperage and frequency.

The object of the invention is to improve the electrical and mechanicalconstruction of such condensers.

The invention comprises the various features described which alsoV areshown in the drawings, of which Figs. l-4 and 8-9 show one form of theinvention, Fig. 1 being a top plan view, partly in section, of a type ofcondenser in which t e invention has been embodied; Fig. 2 a verticalsection taken on the line 2-2 of Fig. 1, looking in the direction of thearrows, and showing the invention; Fig. 3 being a miniature plan view ofa gasket used in the condenser of Figs. 1-2; and Fig. 4 being anenlarged fragmentary view, somewhat diagrammatic and illustratingcertain fused Figs. 5-7 and 10-11 show another form of the invention,Fig. 5 being a vertical sectional view, Fig. 6 being a miniature planview of a gasket used in this form, and Fig. 7 being an enlargedfragmentary View relative to Fig. 5, somewhat diagrammatic andillustrating certain fused connections;

Fig. 8 is a plan view of the high potential connector of the -condenserof Figs. 1-4; Fig. 9 being a side elevation of Fig. 8, partly insection; and

Figs. 10 and 11 are a plan and side elevation respectively of themodified form of connector of the condenser of Figs. 5-7.

The form shown in Figs. 1-4 and 8-9 comprises a plurality of stacks 12,a metal enclosing casing 1, and electrical and thermal leads connectingthe stacks with the condenser terminals. The invention relates mostparticularly to the terminal leads.

Metal casing 1 is one terminal and the upper portion of member 5 withscrews S3 constitute the other terminal. Casing' 1 preferably is analuminum die-casting;

Member 5 is of metal, and is shown in detail in Figs. 8-9 and inassembly most clearly in Fig; 2. Its lower end is abutted by the innerends of all the multiplicity of stacks.

CONDENSER 1926. Serial No. 103,246.

The leads to both terminals are adapted for efficiency in theconductivity of both ele'ctricity and heat. -Leads 4 and 13 are desir`able particularly when the condenser is to be sub'ijected to service at15 am eres or more; gas ret 4 not being necessary or low currentservice. Lead 5 is admirably adapted for all service whetherat high orlow current but particularlyfor high current service.

The con-densers shown are adapted for high potential duty, each stackcomprising a plurality of sections; the sections being separated fromone another at their faces by insulating (mica) plates, Figs. 2 and 4,but the foil-armatures of each section bein fused (soldered) to those ofadjacent sections, so that all the sections are connected in series topermit high potential difference across the ends of the stack. Thetotalstacked elements are divided into the four short stacks 12 shown, inorder to reduce the heat-path byV splitting the total path into fourshort paths. Some of the heat generated in the stack is dissipated inthis Way by conduction lengthwise of the stacks by' conduction via thefoil and mica stack sheets to the ends of the stack and thence bymetallic conduction to surfaces exposed to air outside casing 1. Therest of the heat generated is conducted by the insulating embedment E(as paraiiin Wax), from the edges of the stack sheets to metal casing 1;but at best this general type of condenser (with insulation-embeddedstacks of serially-connected sections) is not an efficientheat-dissipator because the only metal heat path from the individualsections is via their serial electrical connection which.

- and proj ecting The division of the stacked elements in Figs. 1-2 intofour separate stacks 12 results in splitting them into four parts whichthermally as well as electrically are in parallel with one another; andit increases the number of surfaces of metal heat-conductors which arein face contact with the 'stacked elements, two of such surfaces (seebelow) being provided for each of the four divided stacks 12. One set ofthese conductors is constituted of the compression members 2 and screwsS1 which conduct to metal casing 1 such heat as can be transferred fromthe faces ofthe outer stack ends to members 2. The faces of the otherends of the short stacks are in thermal contact with fourlat lateralfaces of the lower or wide portions of paddleshaped metal casting 5 ofFigs. 2, 8, and 9, so that all the heat which can be transferred fromthe inner ends of the stacks is conducted via the narrow portion ofpaddle 5 to the outside of casing 1, said narrow portion extendinglaterally beyond the stacks out thru the top opening in casing 1, and tru pyrex glass cover 8 to metal corona shield 10 of large area eX osedto air whence the heat is dissipated. ut in addition other portions ofthe heat generated inside the stacks by high current are conducted awayand dissipated efficiently via the eight electrical connections (seebelow) to casing 1 and paddle 5. First, as to the four parallel l leads13 from the outer ends of the stacks to casing 1, these are such thatwhen combined with the arrangement of paddle r5 to be described, theywill so increase the heat-removal from the stack as to permit this typeof condenser to be operated at upwards of 15 amperes at a practicallylow stack-temperature. These four parallel connections comprise fourwide thin flexible copper 4strips 13, one of which is shown in plan inFig. 1 and two of which are shown in edge view in Fig. 2; and these fourstrips are connected between casu ing 1 and the four stacks 12. For thispurpose use is made of the clamping action of bottom metal cover B, Fig.2, for the bottom opening of casing 1 which is large enough to permitentrance of stacks 12 and paddle 5, and thru which (while casing 1 isinverted) the molten insulating filler is poured after the stacks andpaddle are clamped by the side walls of the casing. In order to make useof such clamping action of cover B, a gasket 4 (Fig. 3) of thin copperis stamped to the configuration of the outer` surface of the bottom edgeof casing 1 around the edge of the bottom filling opening, holes beingformed for the clamping screws S2 (Fig. 2), and inwardly projectinglintegral tabs T being provided which (Fig. 2) project inside the casing.Before embedding filler E is poured in, the four copper strips 13 arefused (as by soldering F, Fig. 4) to the four tabs T,

' of gasket 4, the other ends of strips 13 being remera.

similarly fused tothe armature foils of the outer sections of the fourstacks as shown at F, Fig'. 4. While the heat conduction from say themiddle of each stack via the serial connection of the section foils tothe projecting foil bunch of the outer section is not very great, yetfor such heat as lis so conducted, the above leads' are ample forconduction to casing 1, for the above construction is such that the heatpath is continuously metallic without separating joints, from the foilsof the outer section to metal gasket 4, and the thermal contact of theboth sides of the gasket with metal casing 1 and metal cover B is madevery broad (altho the gasket itself is narrow) by the use of member 4 inthe form of a gasket extending entirely around the rim of the bottomopening, so that the total area of the thermal gasket member is of thesame order as that of the surface contacts between tabs T and strips 13;and furthermore the thermal contact of gasket 4 and casing 1 is greatlyimproved by the clamping action of bottom cover B which is applied, withscrews S2, after casing 1 has been filled with waX-E andthe filler hasfrozen and the entire condenser re-inverted to normal upright position.The soft metal of heat conducting member 4 (as copper) permits itsaction as a true gasket between casing 1 and bottom cover B.

On the other (inner) ends of the stacks is paddle 5. Tothe lower end orwide portion of the paddleare fused the bunches of armature foils whichproject from the four sections which abut the four faces of the paddle(Fig. 4 at F) so that (in addition to the good thermal contact betweenthe end faces of the stacks and metal 'members 2 and 5 clamped theretoby the casing walls) there is continuous metallic conductivity, withoutany separating joints, between the high potential ends of the armaturesystem of each of the four stacks a-nd themetal of paddle 5. And inorder to permit the paddle to conduct away rapidly all such heat as maybe transferred to it from the four end clamped surfaces and from thefour armature systems, the metal in it (Fig. 9) is made continuousandwithout separating joints, as b a single casting and across-sectional area o adequate dimensions extending from its lower endor wide portion in clamped relation to the stackends, to its upper endwhich is in clamping relation with corona shield 10 as a heat-dissipatorto air. As shown in Figs. 8-9 the wide portion of the paddle is adaptedto rovide surfaces of sufficient area to cover the c amped stack-ends,said wide portion being made metallically continuous with the narrowupper portion (which is preferably cylindrical) by a curvature of thecasting providing adequate mechanical strength. 4 The narrow portion isformed with a shoulder L (Fig. 9)v to form a yet narrower portionreceiving metal washers S4 and 6, terminal screws S3 (Fig. 2) and alsoyielding glass bowl cover 8; and at narrowest portion is threaded at H(Fig. 9) to receive said mal), the one, 13, extending from the outerends of each armature system to metal gasket 4 clamped toheat-dissipating casing 1, and the other, 5, extending from the innerends of each armature system to the metal washer 6 clamped toheat-dissipating bell 10; this construction possessing all theadvantages zo above pointed out.

In Fig. 2 the material S7 shown between the threaded narrow portion ofpaddle 5 and the wall of the opening thru glass bowl 8 is ordinaryadhesive tape used as a buffer between 5A and 8 to prevent the formerfrom chipping the latter. Pyrex bowl 8 is secured to casing 1 by cementin the groove shown in the `casing-rim around the top casingopening.

As shown in Figs. 9 and 2, the wide portion of paddle 5 is hollow andthe narrow portion or paddle handle is solid, the crosssectional area ofeach being substantially the same, for heat conduction; and the bottomof the hollow wide portion of the paddle is open toward the bottomfilling'opening so that the molten filler readily can fill up the hollowof the paddle which is a high potential part.

Figs. 5-7 and 10-11 show modified forms of the leads above described.The stack system consists of onl one pair of stacks instead of the twopalrs, four in all, in the socalled clover-leaf form of Figs. -1-4.Hence the wide portion of paddle 5 is wide in area but not in thicknessand is solid instead of i hollow as in the cubical form of Figs. 1-2;but it possesses all the other characteristics of the form of Figs. 1-2including the metallically continuous and adequate cross-sectionaldimensions suitable for conducting away all heat supplied to it withoutany in-v terruption as by a joint causing discontinuity of conduction.The rate of conduction of heat thru any system is so very slow that theconstruction of this paddle in any form is very advantageous. 4

The shape of the metal casing of Fig. 5 is conformed to the single pairof stacks, and themetal gasket 4 of Fig. 6 is conformed to the shape ofthat casing. The casing here has no bottom opening, and a metal cover Bis interposed between casing 1 and pyrex cover 8, the cover B beingformed with the groove in which cover 8 is secured by cement C. In thisform the molten filler E is poured into the casing thru the top opening,as into gaskets 9 against Aa temporary mold in which a portion El of waxis cast around the narrow p ortion of paddle 5 to approximately the topof glass cover B. In this arrangement (the mode of y assembly of whichdiffers from that of Figs.

1-2), the metal gasket is laid on the top rim of casing 1; but as inFig. 2 the flexible copper strips 13 are fused (F, Fig. 7 to the outerfoil bunches of each stack and also to the integral tabs T, on gasket 4.

The advantages of the invention have been stated above.

I particularly point out and distinctly claim the part, improvement, orcombination which I claim as my-invention discovery, as follows 1. Ahigh duty electrical condenser of the insulation-embedded type, whichcomprises la pair of series-sectional stacks having foil armatures; apaddle-shaped metal casting located between adjacent inner ends of the Ystacks; a metal gasket; and two flexible metal strips; said stacks,paddle and'y strips being enclosed by a metal casing having a largeopening for insertion of the stacks and having a smaller opening closedby an insulating cover, the narrow portion of the paddle prov jectingoutside the casing thru the insulating cover and supported by saidcover; the stacks and the intervening wide portion of the metal paddlebeing clamped together by means of the metal casing walls, and theintervening wide portion of the metal paddle being fused with the foilarmatures of sections yof the stacks adjacent it; the ends of theflexible Vstri s being fused respectively to the metal gas et and to.the foils of the outer stacksections nearer the casing walls; and themetal gasket being clamped to the metal casing around the -large openingtherein by means of the metal cover for'said opening, the metal casingcontaining an insulating embedment.

2. A high duty electrical condenser which comprises a pair ofseries-sectional stacks; a paddle-shaped metal casting located betweenadjacent inner ends of the stacks; a metal gasket; and twoiexible metalstrips; said i stacks, paddle and strips being enclosed by a metalcasing having openings in opposite walls, an insulating cover for oneopening and a metal cover for the other opening; the narrow portion ofthe paddle projecting out thru the insulating cover and supportedthereby, and the wide portion of the paddle extending over the adjacentfaces of end sections of the stacks and fused with-the armatures of saidsections; the ends of tle fiexible metal strips being fused respectivelyto the metal gasket and to the armatures of the outer sections ofthe'stacks; and the metal gasket being clamped to the metal casing bythe` metal casing cover.

3. In an electrical condenser of the type having as one terminal a metalcasing enclosing the condenser elements and having an opening closed bya cover, the means connecting the casing and condenser elements which 5comprises a metal gasket shaped to the conguration of the outside of thecasing at its opening adapting it to be clamped to the metal of thecasing by the cover for the opening; said gasket having inwardlyprojecting tabs adapting it for electrical connection with the enclosedcondenser armatures.

4. In an electrical condenser of the type having as one terminal a metalcasing enclosing the condenser elements and having an opening closed bya cover7 the means connecting the casing and condenser elements whichcomprises a metal gasket shaped to the configuration of the outside ofthe casing at its opening'andV clamped to the metal of the casing by thecasing-cover;' and a flexible metal strip fused to said gasket and tothe condenser armatures.

5. A high duty electrical condenser coinprising a plurality ofseries-sectional stacks having adjacent ends electrically connectedtogether; a metal casing enclosing the stacks and having an openingprovided With a clamping cover; a metal gasket clamped in electricalconnection With the casing by said cover; and a plurality of flexiblemetal strips each fused at one end to said metal gasket, the other endsof the strips being electrically connected With the outer sections ofthe stacks 'which lie nearer the metal casing.

6. ln an electrical condenser of the type having as one terminal a metalcasing enclosing stacked condenserelements and having an opening and acover therefor, the terminal leads comprising a metal 'gasket a0 clampedto the metal casing by said cover, and electrically connected as thecondenser lead of one polarity; and a paddle-shaped metal casting havingits Wide portion formed with a flat face engaged by the stackedcondenser elements and having its narrow portion extending laterallybeyond said elements as the condenser lead of opposite polarity.

ln testimony whereof.2 l hereunto alix my signature.

BENJAMIN .i nnriirin.

